Kasaoka city center area Aerial photograph

is a

city A city is a human settlement of a substantial size. The term "city" has different meanings around the world and in some places the settlement can be very small. Even where the term is limited to larger settlements, there is no universally agree ...

located in

Okayama Prefecture is a Prefectures of Japan, prefecture of Japan located in the Chūgoku region of Honshu. Okayama Prefecture has a population of 1,826,059 (1 February 2025) and has a geographic area of 7,114 Square kilometre, km2 (2,746 sq mi). Okayama Prefecture ...

, Japan. , the city had an estimated

population Population is a set of humans or other organisms in a given region or area. Governments conduct a census to quantify the resident population size within a given jurisdiction. The term is also applied to non-human animals, microorganisms, and pl ...

of 45,404 in 21,987 households and a

population density Population density (in agriculture: Standing stock (disambiguation), standing stock or plant density) is a measurement of population per unit land area. It is mostly applied to humans, but sometimes to other living organisms too. It is a key geog ...

of . The total area of the city is . The municipal district also includes 31 outlying islands including seven inhabited islands in the

Kasaoka Islands The are a group of 31 islands in the Seto Inland Sea of Okayama Prefecture is a Prefectures of Japan, prefecture of Japan located in the Chūgoku region of Honshu. Okayama Prefecture has a population of 1,826,059 (1 February 2025) and has a ge ...

archipelago in the

Seto Inland Sea The , sometimes shortened to the Inland Sea, is the body of water separating Honshu, Shikoku, and Kyushu, three of the four main islands of Japan. It serves as a waterway connecting the Pacific Ocean to the Sea of Japan. It connects to Osaka Ba ...

Geography

Kasaoka is in the far southwestern corner of Okayama Prefecture, bordered by the Seto Inland Sea to the south and Hiroshima Prefecture to the west. It is mostly hilly and mountainous in the north, and consists of flat

reclaimed land Land reclamation, often known as reclamation, and also known as land fill (not to be confused with a waste landfill), is the process of creating new land from oceans, seas, riverbeds or lake beds. The land reclaimed is known as reclamatio ...

in the south. Urbanization is very diffuse, with the main urban concentration at the former port town of Kasaoka, with numerous hamlets scattered widely in narrow valley-shaped plains mostly in the central and northern areas. The

tidal flat Mudflats or mud flats, also known as tidal flats or, in Ireland, slob or slobs, are coastal wetlands that form in intertidal areas where sediments have been deposited by tides or rivers. A global analysis published in 2019 suggested that tidal ...

s in the south are noted for endangered

horseshoe crab Horseshoe crabs are arthropods of the family Limulidae and the only surviving xiphosurans. Despite their name, they are not true crabs or even crustaceans; they are chelicerates, more closely related to arachnids like spiders, ticks, and scor ...

s and the sea area between Kōnoshima and Nishi-Oshima has been designated as a national Natural Monument.

Adjoining municipalities

Hiroshima Prefecture *

Fukuyama Fukuyama may refer to: People * Francis Fukuyama, Japanese-American philosopher and political economist * Fukuyama (surname), other people with the name Places *Fukuyama, Hiroshima, city in Japan *Fukuyama, Kagoshima was a town located in Aira D ...

* Asakuchi *

Ibara is a city located in Okayama Prefecture, Japan. , the city had an estimated population of 37,835 in 16,677 households and a population density of 160 persons per km2. The total area of the city is . Geography Ibara is located in west-central O ...

* Satoshō * Yakage

Climate

Kasaoka has a

humid subtropical climate A humid subtropical climate is a subtropical -temperate climate type, characterized by long and hot summers, and cool to mild winters. These climates normally lie on the southeast side of all continents (except Antarctica), generally between ...

(

Köppen climate classification The Köppen climate classification divides Earth climates into five main climate groups, with each group being divided based on patterns of seasonal precipitation and temperature. The five main groups are ''A'' (tropical), ''B'' (arid), ''C'' (te ...

''Cfa''). The average annual temperature in Kasaoka is . The average annual rainfall is with July as the wettest month. The temperatures are highest on average in August, at around , and lowest in January, at around . The highest temperature ever recorded in Kasaoka was on 5 August 2021; the coldest temperature ever recorded was on 27 February 1981.

Demographics

Per Japanese census data, the population of Kasaoka in 2020 is 46,088 people. Kasaoka has been conducting censuses since 1950.

History

The Kasaoka area is part of ancient

Bitchū Province was a province of Japan on the Inland Sea side of western Honshū, in what is today western Okayama Prefecture. It was sometimes called , with Bizen and Bingo Provinces; those three provinces were settled in the late 7th Century, dividing form ...

and numerous

shell midden A midden is an old landfill, dump for domestic waste. It may consist of animal bone, bones, feces, human excrement, botanical material, mollusc shells, potsherds, Lithic flake, lithics (especially debitage), and other Artifact (archaeology), ...

s from the

Jōmon period In Japanese history, the is the time between , during which Japan was inhabited by the Jōmon people, a diverse hunter-gatherer and early agriculturalist population united by a common culture, which reached a considerable degree of sedentism an ...

confirm that the area has been inhabited since prehistoric times. The place name 'Kasaoka' is said to have been derived from the area of influence of the 'Kasaomi clan' of the ancient

Kingdom of Kibi was a kingdom of fourth century Western Japan. The Kingdom of Kibi covered most of what is today Okayama Prefecture. Today, the Kibi Road crosses the plain between Okayama and Soja, what was once the heartland of ''Kibi no kuni''. Etymology In Ja ...

. Kasaoka Castle, was built by Murakami Takashige at the end of the

Muromachi period The , also known as the , is a division of Japanese history running from approximately 1336 to 1573. The period marks the governance of the Muromachi or Ashikaga shogunate ( or ), which was officially established in 1338 by the first Muromachi ...

and was controlled by the

Mōri clan The was a Japanese clan, Japanese samurai clan descended from Ōe no Hiromoto. Ōe no Hiromoto was descended from the Fujiwara clan. The family's most illustrious member, Mōri Motonari, greatly expanded the clan's power in Aki Province. Durin ...

during the

Sengoku period The was the period in History of Japan, Japanese history in which civil wars and social upheavals took place almost continuously in the 15th and 16th centuries. The Kyōtoku incident (1454), Ōnin War (1467), or (1493) are generally chosen as th ...

. Under the Edo Period

Tokugawa shogunate The Tokugawa shogunate, also known as the was the military government of Japan during the Edo period from 1603 to 1868. The Tokugawa shogunate was established by Tokugawa Ieyasu after victory at the Battle of Sekigahara, ending the civil wars ...

, the area became part of the territory of the

Mizuno clan The Mizuno clan, a prominent Japanese clan, held the esteemed positions of samurai and nobility. Throughout the tumultuous Sengoku period, they were the rulers of Kariya Castle in Mikawa Province, which also served as the ancestral home of Tok ...

Fukuyama Domain file:Abe Masahiro Portrait.png, 270px, Abe Masahiro 7th daimyo of Fukuyama was a Han (Japan), feudal domain under the Tokugawa shogunate of Edo period Japan, in what is now southeastern Hiroshima Prefecture. It controlled much of Bingo Province ...

. The Mizuno invested vast sums of money in

civil engineering Civil engineering is a regulation and licensure in engineering, professional engineering discipline that deals with the design, construction, and maintenance of the physical and naturally built environment, including public works such as roads ...

projects to promote the development of new rice fields in Kasaoka, which originally had little flat land. However, the domain fell to attainder in the middle of the

Edo period The , also known as the , is the period between 1600 or 1603 and 1868 in the history of Japan, when the country was under the rule of the Tokugawa shogunate and some 300 regional ''daimyo'', or feudal lords. Emerging from the chaos of the Sengok ...

, and the Kasaoka area was ruled as ''

tenryō The Tokugawa shogunate, also known as the was the military government of Japan during the Edo period from 1603 to 1868. The Tokugawa shogunate was established by Tokugawa Ieyasu after victory at the Battle of Sekigahara, ending the civil war ...

'' territory about 170 years until the end of the Edo period. Following the

Meiji restoration The , referred to at the time as the , and also known as the Meiji Renovation, Revolution, Regeneration, Reform, or Renewal, was a political event that restored Imperial House of Japan, imperial rule to Japan in 1868 under Emperor Meiji. Althoug ...

, the village of Kasaoka was established within

Oda District, Okayama is a district located in Okayama Prefecture, Japan. As of 2003, the district has an estimated population of 21,285 and a population density Population density (in agriculture: Standing stock (disambiguation), standing stock or plant density) ...

with the creation of the modern municipalities system on June 1, 1889. It was raised to town status on October 23, 1891 and to city status on April 1, 1952. Due to its strong historical, cultural and economic ties with Fukuyama, proposals have been made for a merger between the two municipalities.

Government

Kasaoka has a mayor-council form of government with a directly elected mayor and a

unicameral Unicameralism (from ''uni''- "one" + Latin ''camera'' "chamber") is a type of legislature consisting of one house or assembly that legislates and votes as one. Unicameralism has become an increasingly common type of legislature, making up nearly ...

city council of 17 members. Kasaoka contributes two members to the Okayama Prefectural Assembly. In terms of national politics, the city is part of the Okayama 3rd district of the

lower house A lower house is the lower chamber of a bicameral legislature, where the other chamber is the upper house. Although styled as "below" the upper house, in many legislatures worldwide, the lower house has come to wield more power or otherwise e ...

of the

Diet of Japan , transcription_name = ''Kokkai'' , legislature = 215th Session of the National Diet , coa_pic = Flag of Japan.svg , house_type = Bicameral , houses = , foundation=29 November 1890(), leader1_type ...

Economy

Kasaoka is located in the Seto Inland Sea Industrial Belt and together with neighboring Fukuyama was designated in 1964 as the "Bingo District Special Industrial Development Area". The city has a high concentration of heavy industry, notably related to

JFE Steel JFE Steel () is the second largest Japanese steel manufacturer (after Nippon Steel). The company was created in 2002 through the merger of the steel manufacturing business of Kawasaki Steel and NKK (Nihon Kokan). It is owned by JFE Holdings, wh ...

, a major producer of crude steel in Japan. Agriculture, food processing are also major contributors to the local economy, although the traditional industries stone quarrying and production of

pyrethrum ''Pyrethrum'' was a genus of several Old World plants now classified in either '' Chrysanthemum'' or '' Tanacetum'' which are cultivated as ornamentals for their showy flower heads. Pyrethrum continues to be used as a common name for plants form ...

are in decline due to competition from foreign sources. The city is also increasing a

commuter town A commuter town is a populated area that is primarily residential rather than commercial or industrial. Routine travel from home to work and back is called commuting, which is where the term comes from. A commuter town may be called by many o ...

for neighboring Fukuyama and Kurashiki.

Education

Kasaoka has 18 public elementary schools and nine public junior high schools operated by the city government and one private junior high school. The city has four public high schools operated by the Okayama prefectural Board of Education. The prefecture also operates one special education school for the disabled.

Transportation

Railway

JR West , also referred to as , is one of the Japan Railways Group (JR Group) companies and operates in western Honshu. It has its headquarters in Kita-ku, Osaka. It is listed in the Tokyo Stock Exchange, is a constituent of the TOPIX Large70 index, ...

(JR West) -

San'yō Main Line The is a major railway line owned by JR Group companies in western Japan, connecting Kōbe Station and Moji Station, largely paralleling the coast of the Seto Inland Sea, in other words, the southern coast of western Honshu. The San'yō Shi ...

Highways

San'yō Expressway The (Asian Highway Network ) is an expressway in Japan, running from Kobe through Hiroshima along the Inland Sea and terminating in Yamaguchi Prefecture. The entire length of the expressway was opened in 1997. The main line has a total length of ...

Sister cities

Kasaoka is twinned with: *

Astoria, Oregon Astoria is a Port, port city in and the county seat of Clatsop County, Oregon, United States. Founded in 1811, Astoria is the oldest city in the state and was the first permanent American settlement west of the Rocky Mountains. The county is the ...

, United States *

Goseong County Goseong may refer to: * Goseong County, South Gyeongsang, a county in South Gyeongsang Province, South Korea * Goseong County, Gangwon, a county in Gangwon Province, South Korea * Kosong County Kosŏng () is a '' kun'', or county, in Kangwŏn pr ...

, South Korea *

Kota Bharu Kota Bharu ( Kelantanese: ''Koto Baghu''), colloquially referred to as KB, is a town in Malaysia that serves as the state capital and royal seat of Kelantan. It is situated in the northeastern part of Peninsular Malaysia and lies near the mout ...

, Kelantan, Malaysia *

Mörbylånga Mörbylånga is a locality situated on the southern part of the island of Öland and is the seat of Mörbylånga Municipality, Kalmar County, Sweden with 1,780 inhabitants in 2010. Other settlements in southern Öland are Alby, the site of a M ...

, Sweden *

Ōda, Shimane file:Oda city hall-b.jpg, 270px, Ōda City Hall file:Oda city center area Aerial photograph.1976.jpg, 270px, Aerial view of central Ōda file:180505 Yunotsu of Iwami Ginzan Silver Mine Oda Shimane pref Japan01s5.jpg, 270px, Yunotsu area of Ōda ...

, Japan

Landmarks and local cultural facilities

* Kasaoka is the location of a protected

breeding habitat and the city features a Horseshoe Crab Museum. * Chikkyo Art Museum *

Tsukumo Shell Mound The is an archaeological site in the Nishioshima neighborhood of the city of Kasaoka, Okayama, Kasaoka, Okayama Prefecture, in the San'yō region of western Japan. It contains a Jōmon period midden, shell midden, and was designated a Monuments ...

, National Historic Site * In culinary terms, Kasaoka city is known for its abundance of sea food and a local specialty of chicken based ramen.

Crime and safety

The Asano-gumi

yakuza , also known as , are members of transnational organized crime syndicates originating in Japan. The Japanese police and media (by request of the police) call them , while the yakuza call themselves . The English equivalent for the term ''yak ...

syndicate is based in Kasaoka. The Asano-gumi is the only designated yakuza group based in Okayama Prefecture."2010 Police White Paper Chapter 2 : Furtherance of Organized Crime Countermeasures"
2010, ''

National Police Agency National Police may refer to the national police forces of several countries: *Afghanistan: Afghan National Police *Haiti: Haitian National Police *Canada: Royal Canadian Mounted Police *Colombia: National Police of Colombia *Cuba: National Revolut ...

References

External links

*
Kasaoka City official website
{{Authority control Cities in Okayama Prefecture Kasaoka, Okayama Populated coastal places in Japan